1. Field of the Invention
The present invention generally relates to methods for making patterned masks of resist material and, more particularly, to a controlled resist reflow process for reducing resist aperture dimensions.
2. Description of the Prior Art
One of the major factors, i.e., device size, governing integrated semiconductor device speed and performance is determined by the dimensions of the openings in patterned resist masks used in etching and diffusion processes. Because of inherent characteristics such as, for example, reduced capacitance smaller sized devices generally exhibit superior performance and facilitate the design of high density integrated circuits. Efforts toward making smaller sized devices are confronted with the ultimate resolution with which resist material can be sensitized prior to development of the resist. In the case of photosensitive resist material, there is significant difficulty in achieving line resolutions smaller than 100 micro inches. Electron beam lithography techniques encounter serious difficulties when windows of less than 50 micro inches are desired.